Embodiments relate to a light emitting device package, a lighting device, and an image display device.
Light emitting devices (LEDs), which are semiconductor devices for converting electrical energy into light energy, may emit light of various wavelengths (colors), such as red, green, blue, and ultraviolet rays, by controlling a composition of a semiconductor compound, and generate white light having high efficiency, by using a phosphor or combining colors.
LEDs have advantages such as low power consumption, a semi-permanent life cycle, a fast response time, safety, and environment friendly when compared to typical light sources such as fluorescent lamps and incandescent bulbs. Accordingly, LEDs are being widely used in light emitting diode backlights that replace cold cathode fluorescence lamps (CCFLs) constituting backlights of liquid crystal display (LCD) devices, white light emitting diode lighting devices that replace fluorescent lamps and incandescent lamps, vehicle headlamps, and traffic lights.
In light emitting device packages according to the related art, a light emitting device chip is mounted on a package body, and an electrode layer is disposed on the package body and electrically connected to the light emitting chip. A resin layer including a phosphor is disposed on the light emitting device chip, and a molding part having a predetermined lens shape is disposed on the resin layer.
However, the light emitting device package according to the related art may have a limitation related to reliability when the light emitting device package is operated under a high-temperature high-moisture state.
For example, according to the related art, since an adhesion between the lens molding part and the electrode layer may be weak, the light emitting device package may be vulnerable to moisture introduction. Thus, sealing quality may be deteriorated, and thus the moisture may be penetrated up to a metal layer or a die adhesive of the light emitting device chip to allow the metal layer or the die adhesive to fade, thereby reducing light efficiency.
Also, according to the related art, since the lens molding part has an elastic modulus greater than that of the electrode layer, a thermal stress may occur. In this case, since a structure for preventing the lens molding part from being deformed due to the thermal stress is not provided, the lens molding part may be delaminated to accelerate the penetration of the moisture when the moisture is introduced.